Semiconductor device and manufacturing method of semiconductor device

ABSTRACT

The present invention provides a thin and bendable semiconductor device utilizing an advantage of a flexible substrate used in the semiconductor device, and a method of manufacturing the semiconductor device. The semiconductor device has at least one surface covered by an insulating layer which serves as a substrate for protection. In the semiconductor device, the insulating layer is formed over a conductive layer serving as an antenna such that the value in the thickness ratio of the insulating layer in a portion not covering the conductive layer to the conductive layer is at least 1.2, and the value in the thickness ratio of the insulating layer formed over the conductive layer to the conductive layer is at least 0.2. Further, not the conductive layer but the insulating layer is exposed in the side face of the semiconductor device, and the insulating layer covers a TFT and the conductive layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductor devices including circuitelements and a manufacturing method of the semiconductor devices.Further, the present invention relates to semiconductor devices whichcan conduct data communication with wireless communication.

2. Description of the Related Art

Currently, it is important to make thin-mode various devices such aswireless chips and sensors in miniaturizing products, and thetechnologies and the application range spread rapidly. Such variousthin-mode devices are flexible to some extent and thus the devices canbe set in an object having a curved surface. IC chips in which anintegrated circuit is formed on a flexible substrate, and the like havebeen proposed (for example, Japanese Published Patent Application No.2006-19717).

SUMMARY OF THE INVENTION

However, in a conventional technique, it is necessary to cover a surfaceof a device by a somewhat hard substrate in order to protect the device.The substrate is flexible but is hard because it has a somewhat largethickness, and thus, a device itself using the substrate becomes thick,which leads to prevention of the flexibility of the device. Therefore,for example, an object provided with the device gives a user a feelingof strangeness. So far, devices which make full use of a flexiblesubstrate have not been provided. In view of the above, the presentinvention provides semiconductor devices which are thinner and morebendable, and a method of manufacturing such semiconductor devices.

A semiconductor device of the present invention has at least one surfacecovered by an insulating layer (protective film) which serves as asubstrate for protection. In the semiconductor device, the insulatinglayer (also referred to as an insulating film) is formed over aconductive layer serving as an antenna such that the value in thethickness ratio of the insulating layer in a portion not covering theconductive layer (also referred to as a conductive film) to theconductive layer is at least 1.2, and the value in the thickness ratioof the insulating layer formed over the conductive layer to theconductive layer is at least 0.2. In other words, the insulating layeris formed over the conductive layer such that the thickness ratio of theconductive layer serving as an antenna to the insulating layer notcovering the conductive layer is 1:1.2, and the thickness ratio of theconductive layer to the insulating layer formed over the conductivelayer is at least 1:0.2. Further, not the conductive layer but theinsulating layer is exposed in the side face of the semiconductordevice, and the insulating layer covers a TFT and the conductive layer.In addition, in the semiconductor device of the present invention, as asubstrate covering an element formation layer side, a substrate having asupport on its surface is used in the manufacturing process.

An aspect of the present invention is a semiconductor device whichincludes an element formation layer formed over a substrate; a storageelement portion formed over the element formation layer; a conductivelayer serving as an antenna formed over the element formation layer; anda resin layer formed over the element formation layer, the storageelement portion and the conductive layer serving as an antenna. In thesemiconductor device, a value in a thickness ratio of the resin layer ina portion not covering the conductive layer to the conductive layer isat least 1.2, and a value in a thickness ratio of the resin layer formedover the conductive layer to the conductive layer is at least 0.2.

Another aspect of the present invention is a semiconductor device whichincludes an element formation layer formed over a substrate; a storageelement portion formed over the element formation layer; a conductivelayer serving as an antenna formed over the element formation layer; anda protective film formed over the element formation layer, the storageelement portion and the conductive layer serving as an antenna. In thesemiconductor device, a value in a thickness ratio of the protectivefilm in a portion not covering the conductive layer to the conductivelayer is at least 1.2, and a value in a thickness ratio of theprotective film formed over the conductive layer to the conductive layeris at least 0.2.

Another aspect of the present invention is a semiconductor device whichincludes an element formation layer formed over a substrate; a storageelement portion formed over the element formation layer; a conductivelayer serving as an antenna formed over the element formation layer; anda resin layer formed over the element formation layer, the storageelement portion and the conductive layer serving as an antenna. In thesemiconductor device, the element formation layer comprises a circuitfor writing in data into the storage element portion and reading outdata from the storage element portion, and a first semiconductor layer(also referred to as a semiconductor film) including an n-type impurityregion and a p-type impurity region which are jointed, the circuitincludes a plurality of thin film transistors, the first semiconductorlayer is formed over the same surface as a second semiconductor layer ofthe thin film transistor, and a value in a thickness ratio of the resinlayer in a portion not covering the conductive layer to the conductivelayer is at least 1.2, and a value in a thickness ratio of the resinlayer formed over the conductive layer to the conductive layer is atleast 0.2.

Another aspect of the present invention is a semiconductor device whichincludes an element formation layer formed over a substrate; a storageelement portion formed over the element formation layer; a conductivelayer serving as an antenna formed over the element formation layer; anda protective film formed over the element formation layer, the storageelement portion and the conductive layer serving as an antenna. In thesemiconductor device, the element formation layer comprises a circuitfor writing in data into the storage element portion and reading outdata from the storage element portion, and a first semiconductor layerincluding an n-type impurity region and a p-type impurity region whichare jointed, the circuit includes a plurality of thin film transistors,the first semiconductor layer is formed over the same surface as asecond semiconductor layer of the thin film transistor, and a value in athickness ratio of the protective film in a portion not covering theconductive layer to the conductive layer is at least 1.2, and a value ina thickness ratio of the protective film formed over the conductivelayer to the conductive layer is at least 0.2.

In the semiconductor device of the present invention, the resin layer isformed of epoxy resin.

In the semiconductor device of the present invention, the protectivelayer is formed of epoxy resin.

In the semiconductor device of the present invention, the substrate hasa thickness of 2 μm to 20 μm, inclusive.

In the semiconductor device of the present invention, the elementformation layer is formed over the substrate with an adhesive layertherebetween.

Another aspect of the present invention is a method of manufacturing asemiconductor device includes the steps of forming a peeling layer overa first substrate; forming an element formation layer over the peelinglayer; forming a storage element portion and a conductive layer servingas and an antenna over the element formation layer; forming a protectivefilm over the element formation layer, the storage element portion andthe conductive layer serving as an antenna; forming a second substrateover the protective film, and separating the first substrate from theelement formation layer, using the second substrate; forming the elementformation layer to be in contact with a third substrate having a supportwith an adhesive layer therebetween; and removing the second substrateand the support.

In the semiconductor device of the present invention, wherein the secondsubstrate has a thickness of 2 μm to 20 μm, inclusive.

In the semiconductor device of the present invention, the resin layer isformed of epoxy resin.

A semiconductor device of the present invention has at least one surfacecovered by a resin. Thus, in the semiconductor device, a storage elementportion and an element formation layer below the resin layer can beprotected from dusts and the like, and the mechanical strength of thesemiconductor device can be kept. Further, in the semiconductor deviceof the present invention, a resin layer is used as a substrate coveringat least one surface, and thus a semiconductor device which is thin andbendable can be provided.

In the semiconductor device of the present invention, the insulatinglayer is formed over the conductive layer serving as an antenna suchthat the thickness ratio of the insulating layer in a portion notcovering the conductive layer to the conductive layer serving as anantenna is at least 1.2, and the thickness ratio of the insulating layerformed over the conductive layer to the conductive layer is at least0.2. Thus, the surface of the insulting layer has a sufficient planarityto reduce damages to the element formation layer in a manufacturingprocess of the semiconductor device. In addition, a semiconductor devicehaving a mechanical strength enough to protect a storage element portionand an element formation layer can be obtained.

In the semiconductor device of the present invention, a conductive layeris not exposed in the side face of the semiconductor device, and aninsulating layer covering a TFT and the conductive layer is exposed.Thus, elements such as a TFT or an antenna can be protected from dustsand the like by only the insulating layer covering the conductive layerserving as an antenna, and thus the semiconductor device which does noteasily deteriorate can be provided.

In addition, in the semiconductor device of the present invention, as asubstrate covering an element formation layer side, a substrate having asupport on its surface is used in the manufacturing process, and thus,the substrate having a thickness of 2 μm to 20 μm can be easily handled.Therefore, a semiconductor device which is thin and bendable can beeasily manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A and 1B illustrate a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 2A to 2C illustrate a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 3A and 3B illustrate a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 4A and 4B illustrate a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 5A and 5B illustrate a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIG. 6 illustrates a process of manufacturing a semiconductor deviceaccording to an aspect of the present invention;

FIG. 7 illustrates a process of manufacturing a semiconductor deviceaccording to an aspect of the present invention;

FIGS. 8A to 8E illustrate a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 9A to 9D illustrates a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 10A to 10D illustrates a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIGS. 11A to 11C illustrates a process of manufacturing a semiconductordevice according to an aspect of the present invention;

FIG. 12 illustrates a semiconductor device according to an aspect of thepresent invention;

FIGS. 13A and 13B illustrate a semiconductor device according to anaspect of the present invention;

FIGS. 14A and 14B illustrate application modes of a semiconductor deviceaccording to an aspect of the present invention;

FIGS. 15A to 15E illustrate application modes of a semiconductor deviceaccording to an aspect of the present invention; and

FIGS. 16A to 16D illustrate application modes of a semiconductor deviceaccording to an aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment Modes of the present invention are described with referenceto drawings in detail. Note that the present invention can be carriedout in many different modes. It is easily understood by those skilled inthe art that modes and details disclosed herein can be modified invarious ways without departing from the spirit and the scope of thepresent invention. Therefore, it should be noted that the presentinvention should not be interpreted as being limited to the descriptionof the embodiment modes given below. Further, Embodiment Modes 1 to 4can be freely combined with each other. In other words, materials andformation methods to be described in Embodiment Modes 1 to 4 can befreely combined. Note that in the structures of the present invention,similar portions are denoted by the same reference numerals through thedrawings.

(Embodiment Mode 1)

Embodiment Mode 1 will explain an example of a semiconductor device ofthe present invention with reference to drawings.

FIGS. 1A and 1B show a semiconductor device of this embodiment mode.Note that FIG. 1A illustrates an example of a top face structure of thesemiconductor device shown in this embodiment mode, and FIG. 1Billustrates a part of a cross-sectional structure of FIG. 1A.

In this embodiment mode, a semiconductor device 200 includes anintegrated circuit portion 201, a memory section 202 and an antenna 203(FIG. 1A). In FIG. 1B, a region 204 corresponds to a part of thecross-sectional structure of the integrated circuit portion 201 of FIG.1A, a region 205 corresponds to a part of the cross-sectional structureof the memory section 202 of FIG. 1A, and a region 206 corresponds to apart of the cross-sectional structure of the antenna 203 of FIG. 1A.

The semiconductor device of this embodiment mode includes thin filmtransistors (TFTs) 744 to 748 which are formed over a substrate 778 withan insulating layer 703 therebetween, an insulating layer 750 formedover the thin film transistors 744 to 748, and conductive layers 752 to761 serving as source and drain electrodes formed over the insulatinglayer 750 as shown in FIG. 1B. In this embodiment mode, the insulatinglayer 703 is formed over the substrate 778 with an adhesive layertherebetween. Further, in this embodiment mode, there are no particularlimitations on the material of the substrate 778, and a substrate havinga thickness of about 2 μm to 20 μm is used.

In addition, the semiconductor device of this embodiment mode includesan insulating layer 762 formed over the insulating layer 750 and theconductive layers 752 to 761, conductive layers 763 to 765 formed overthe insulating layer 762, an insulating layer 766 formed to cover partsof the insulating layer 762 and the conductive layer 763 to 765, storageelement portions 789, 790 formed over the insulating layer 762, aconductive layer 786 serving as an antenna formed over the conductivelayer 765, and an insulating layer 772 formed to cover the insulatinglayer 766, the conductive layer 771 and the conductive layer 786 servingas an antenna.

The insulating layer 772 in this embodiment mode is preferably formedusing a resin (more preferably, epoxy resin). Epoxy resin is used as theinsulating layer 772, so that the planarity of the surface of theinsulating layer 772 is increased, the storage element portion and theelement formation layer below the insulating layer 772 are protectedfrom dusts and the like, and the mechanical strength of thesemiconductor device can be held. Further, in the semiconductor deviceof this embodiment mode, since the insulating layer 772 can be used as asubstrate covering the conductive layer serving as an antenna, asemiconductor device which is thin and bendable can be provided.Furthermore, in this embodiment mode, the insulating layer 772 may beformed such that the ratio of the thickness of the insulating layer 772in a portion not covering the conductive layer 786 to the thickness ofthe conductive layer 786 serving as an antenna is at least 1.2, and theratio of the thickness of the insulating layer 772 formed over theconductive layer 786 to the thickness of the conductive layer 786 is atleast 0.2. Thus, the surface of the insulating layer 772 can haveplanarity enough to reduce damages to the element formation layer in themanufacturing process of the semiconductor device, and thus, asemiconductor device having mechanical strength enough to protect thestorage element portion and the element formation layer can be obtained.Note that it is natural that the memory section and the integratedcircuit portion shown in FIGS. 1A and 1B have a plurality of elementssuch as TFTs or capacitors.

In this embodiment mode, preferably, the conductive layer is not exposedin the side face of the semiconductor device. In other words, in theside face of the semiconductor device, the insulating layer covering theTFTs and the conductive layer is exposed. By employing such a structure,the present invention can provide a semiconductor device in whichelements such as TFTs Is and an antenna can be protected from dusts andthe like by only the insulating layer 772 and which does not easuktdeteriorate.

Next, an example of a manufacturing process of the semiconductor deviceillustrated in FIGS. 1A and 1B is explained.

A separation layer 702 is formed over one surface of a first substrate701 (see FIG. 2A). The first substrate 701 has an insulating surface.When the first substrate 701 is formed of glass, there are no particularlimitations on the area and shape of the first substrate. Thus, as thefirst substrate 701, for example, a substrate having one side of onemeter or longer and a rectangular shape is used to improve theproductivity drastically. Such advantages are superior points to thoseof circular single crystal silicon substrates. In addition, when thesubstrate 701 is formed of plastic, plastics which can resist heat of atreatment in the manufacturing process are needed. Although describedlater, preferably, after a thin film transistor is formed over the firstsubstrate 701 made of glass, the thin film transistor may be separatedfrom the first substrate 701 and provided over a substrate made ofplastic.

Note that in this manufacturing process, the separation layer 702 isformed over the entire surface of the first substrate 701; however, asnecessary, the separation layer may be provided over the entire surfaceof the first substrate 701 and then patterned by a photolithographymethod to be selectively formed. Alternatively, the separation layer 702is in contact with the first substrate 701; however, as necessary, aninsulating layer serving as a base may be formed to be in contact withthe first substrate 701, and the separation layer 702 may be formed tobe in contact with the insulating layer.

The separation layer 702 is formed using an element such as tungsten(W), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium (Nb), nickel(Ni), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium(Rh), palladium (Pd), osmium (Os), iridium (Ir), or silicon (Si); analloy material or a compound material containing such an element as amain component to have a single layer structure or a laminated layerstructure by a sputtering method, a plasma CVD method or the like. Thecrystal structure of a layer including silicon may be any of amorphous,microcrystal and polycrystal.

Next, an insulating layer 703 serving as a base is formed to cover theseparation layer 702. As the insulating layer 703, a layer including anoxide or a nitride of silicon is formed by a method such as sputteringor CVD to have a single layer structure or a laminated layer structure.A oxide material of silicon is a substance containing silicon (Si) andoxygen (O) and corresponds to silicon oxide, silicon oxide containingnitrogen or the like. A nitride material of silicon is a substancecontaining silicon and nitrogen (N), and corresponds to silicon nitride,silicon nitride containing oxygen or the like. The insulating layerserving as a base functions as a blocking film for preventing impuritiesfrom entering from the first substrate 701.

Subsequently, an amorphous semiconductor layer 704 is formed over theinsulating layer 703. The amorphous semiconductor layer 704 is formed bya sputtering method, an LPCVD method, a plasma CVD method, or the like.Subsequently, the amorphous semiconductor layer 704 is crystallized by acrystallization method (such as a laser crystallization method, athermal crystallization method using RTA or an annealing furnace, athermal crystallization method using a metal element which promotescrystallization, or a combination of a thermal crystallization methodusing a metal element which promotes crystallization and a lasercrystallization method) to form a crystalline semiconductor layer.Thereafter, the obtained crystalline semiconductor layer is patternedinto a desired shape to form crystalline semiconductor layers 706 to 710(see FIG. 2B).

An example of a manufacturing process of the crystalline semiconductorlayers 706 to 710 is explained below. First, an amorphous semiconductorlayer is formed using a plasma CVD method. After applying a solutioncontaining nickel which is a metal element for promoting crystallizationso as to reside over the amorphous semiconductor layer, the amorphoussemiconductor layer is subjected to a dehydrogenating treatment (500° C.for one hour) and a thermal crystallization treatment (550° C. for fourhours) to form a crystalline semiconductor layer. Thereafter, thecrystalline semiconductor layer is irradiated with a laser beam, ifrequired, and pattered by a photolithography method to form thecrystalline semiconductor layers 706 to 710.

In forming the crystalline semiconductor layer by a lasercrystallization method, a gas laser or a solid state laser can be used.The gas laser or the solid state layer may be a continuous wave laser ora pulsed laser. As a laser beam which can be used here, for example, abeam emitted from one or plural kinds of a gas laser such as an Arlaser, a Kr laser, or an excimer laser; a laser using, as a medium,single crystalline YAG, YVO₄, forsterite (Mg₂SiO₄), YAlO₃, or GdVO₄ orpolycrystalline (ceramic) YAG; Y₂O₃, YVO₄, YAlO₃, or GdVO₄ doped withone or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta as a dopant; a glasslaser; a ruby laser; an alexandrite laser; a Ti:sapphire laser; a coppervapor laser; and a gold vapor laser, can be used. Irradiation of a laserbeam of a fundamental wave of such lasers or a second to fourth harmonicof such a fundamental wave can give a crystal with a large grain size.

Note that each laser using, as a medium, single crystalline YAG, YVO₄,forsterite (Mg₂SiO₄), YAlO₃, or GdVO₄ or polycrystalline (ceramic) YAG,Y₂O₃, YVO₄, YAlO₃, or GdVO₄ doped with one or more of Nd, Yb, Cr, Ti,Ho, Er, Tm, and Ta as a dopant; an Ar ion laser; and a Ti:sapphirelaser, can continuously oscillate. Further, pulse oscillation thereofcan be performed with a repetition rate of 10 MHz or more by performingQ switch operation or mode locking. When a laser beam is oscillated at arepetition rate of 10 MHz or more or a CW layer beam is oscillated, thesurface of the crystallized semiconductor layer can be leveled. Thus, agate insulating layer to be formed later can be thinned, therebyproviding a thinner-mode semiconductor device. Thus, the withstandvoltage of a gate insulating layer can be improved.

The crystallization of the amorphous semiconductor layer using a metalelement for promoting crystallization has the advantages of enablingcrystallization at a low temperature in a short time and aligning adirection of crystals; on the other hand, the crystallization has adisadvantage that off current is increased due to the metal elementremaining in the crystalline semiconductor layer and characteristics ofthe crystalline semiconductor layer are not stabilized. Therefore, anamorphous semiconductor layer serving as a gettering site is preferablyformed over the crystalline semiconductor layer. Since the amorphoussemiconductor layer serving as a gettering site should contain animpurity element such as phosphorus or argon, the amorphoussemiconductor layer is preferably formed by a sputtering method by whichthe amorphous semiconductor layer can contain argon at highconcentration. Then, a heat treatment (thermally annealing using an RTAmethod, an annealing furnace, or the like) is performed to diffuse themetal element into the amorphous semiconductor layer. Subsequently, theamorphous semiconductor layer containing the metal element is removed.This makes it possible to reduce or remove the metal element containedin the crystalline semiconductor layer.

Next, a gate insulating layer 705 is formed to cover the crystallinesemiconductor layers 706 to 710. The gate insulating layer 705 is formedby using a single layer or a laminated layer of a film containing anoxide and/or a nitride of silicon by a CVD method, a sputtering method,or the like. In addition, the gate insulating layer may be formed byperforming a high-density plasma treatment on the crystallinesemiconductor layers 706 to 710 and oxidizing or nitriding the surface.For example, the gate insulating layer 705 is formed by a plasmatreatment with an introduced mixed gas of a rare gas such as He, Ar, Kr,or Xe and oxygen, nitrogen oxide (NO₂), ammonia, nitrogen, hydrogen, orthe like. When plasma excitation in this case is performed byintroducing a microwave, high-density plasma can be produced at lowelectron temperature. The surface of the semiconductor layers can beoxidized or nitrided with an oxygen radical (which may include an OHradical) or a nitrogen radical (which may include an NH radical) that isproduced by the high-density plasma.

By a treatment using such high-density plasma, an insulating layer witha thickness of 1 nm to 20 nm, typically, 5 nm to 10 nm, is formed overthe semiconductor layers. A reaction in this case is a solid-phasereaction; therefore, the interface state density between the insulatinglayer and the semiconductor layers can be extremely lowered. Since sucha high-density plasma treatment directly oxidizes (or nitrides) thesemiconductor layers (of crystalline silicon or polycrystallinesilicon), variation in thickness of the insulating layer to be formedcan be ideally suppressed significantly. Furthermore, oxidation is notperformed strongly also at a crystal grain boundary of crystallinesilicon, which leads to an extremely preferable state. In other words,when each surface of the semiconductor layers is subjected tosolid-phase oxidation by the high-density plasma treatment shown here,an insulating layer with low interface state density and favorableuniformity can be formed without causing abnormal oxidation reaction ata crystal grain boundary. Accordingly, a semiconductor device which isthinner and has better characteristics can be provided.

As the gate insulating layer, only an insulating layer formed by ahigh-density plasma treatment may be used. Alternatively, an insulatinglayer of silicon oxide, silicon oxynitride, or silicon nitride may bedeposited or laminated thereover by a CVD method utilizing plasma or athermal reaction. In either case, by forming the gate insulating layerof a transistor to include partially or wholly such an insulating layerformed with high-density plasma, the transistor can have reducedvariations in characteristics. Accordingly, a semiconductor device whichis thinner and has better characteristics can be provided.

The crystalline semiconductor layers 706 to 710, which are formed bycrystallizing the semiconductor layer by irradiation with a continuouswave laser beam or a laser beam oscillated at a repetition rate of 10MHz or more, scanning the semiconductor layer with the laser beam in onedirection, have a feature that crystals grow in the scanning directionof the laser beam. When transistors are arranged such that the scanningdirection is aligned with each a channel length direction (a directionin which carries flow when a channel formation region is formed) and thetransistors are combined with the gate insulating layer, the transistors(TFTs) with little variation in characteristics and high electronfield-effect mobility can be obtained.

Next, a first conductive layer and a second conductive layer arelaminated over the gate insulating layer 705. The first conductive layeris formed by a plasma CVD method, a sputtering method, or the like witha thickness of 20 nm to 100 nm. The second conductive layer is formed bya known method with a thickness of 100 nm to 400 nm. The firstconductive layer and the second conductive layer are formed with anelement such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum(Mo), aluminum (Al), copper (Cu), chromium (Cr), or the like; or analloy material or a compound material containing such an element as itsmain component. Alternatively, the first conductive layer and the secondconductive layer are formed with semiconductor materials typified bypolycrystalline silicon doped with an impurity element such asphosphorus. As an example of a combination of the first conductive layerand the second conductive layer, a layer including tantalum nitride anda layer including tungsten, a layer including tungsten nitride and alayer including tungsten, a layer including molybdenum nitride and alayer including molybdenum, or the like can be given. Since tungsten andtantalum nitride have high heat resistance, a heat treatment for thermalactivation can be performed after forming the first conductive layer andthe second conductive layer. In the case of employing not a two-layerstructure but a three-layer structure, a laminated structure of amolybdenum layer, an aluminum layer, and a molybdenum layer may beemployed.

Next, a mask of resist is formed using a photolithography method and anetching treatment for forming a gate electrode and a gate line isperformed to form conductive layers 716 to 725 functioning as gateelectrodes.

Then, a mask of resist is formed by a photolithography method and animpurity element which imparts N-type conductivity is added to thecrystalline semiconductor layers 706 and 708 to 710 at low concentrationby an ion doping method or an ion implantation method to form impurityregions 711 and 713 to 715 and channel formation regions 780 and 782 to784. As the impurity element which imparts N-type conductivity, anelement belonging to Group 15 may be used and, for example, phosphorus(P) or arsenic (As) is used.

Then, a mask of resist is formed by a photolithography method and animpurity element which imparts P-type conductivity is added to thecrystalline semiconductor layer 707 to form an impurity region 712 and achannel formation region 781. As the impurity element which impartsP-type conductivity, for example, boron (B) is used.

Next, an insulating layer is formed to cover the gate insulating layer705 and the conductive layers 716 to 725. The insulating layer is formedby using a single layer or a laminated layer of a layer containing aninorganic material such as silicon, an oxide and/or a nitride of siliconor a layer containing an organic material such as an organic resin by aplasma CVD method, a sputtering method, or the like. Next, theinsulating layer is selectively etched by anisotropic etching, in whichetching is performed mainly in a perpendicular direction, to forminsulating layers (also referred to as sidewalls) 739 to 743 in contactwith side faces of the conductive layers 716 to 725 (see FIG. 2C). Atthe same time as the manufacturing of the insulating layers 739 to 743,the insulating layer 705 is etched to form insulating layers 734 to 738.The insulating layers 739 to 743 are used as masks for doping whenforming LDD (lightly doped drain) regions later.

Subsequently, a mask of resist is formed by a photolithography method,an impurity element which imparts N-type conductivity is added to thecrystalline semiconductor layers 706 and 708 to 710 to form firstimpurity regions 727, 729, 731, and 733 serving as LDD (Lightly DopedDrain) regions and second impurity regions 726, 728, 730, and 732, usingthe mask of resist and the insulating layers 739 to 743 as masks. Theconcentration of the impurity element contained in the first impurityregions 727, 729, 731, and 733 is lower than that in the second impurityregions 726, 728, 730, and 732. Through the above steps, N-channel thinfilm transistors 744 and 746 to 748 and a P-channel thin film transistor745 are completed.

Subsequently, a single layer or laminated layer of an insulating layeris formed to cover the thin film transistors 744 to 748 (FIG. 3A). Theinsulating layer covering the thin film transistors 744 to 748 is formedby an SOG method, a droplet discharge method, or the like with a singlelayer or a laminated layer of an inorganic material such as an oxideand/or a nitride of silicon, an organic material such as polyimide,polyamide, benzocyclobutene, acrylic, epoxy, or siloxane, or the like.Siloxane is a resin containing Si—O—Si bond. Siloxane has a skeletonstructure including a bond of silicon (Si) and oxygen (O). As asubstituent, an organic group including at least hydrogen (for example,an alkyl group, and aromatic hydrocarbon) is used. Further, a fluorogroup may be used as a substituent.

For example, in the case where the insulating layer covering the thinfilm transistors 744 to 748 has a three-layer structure, a layercontaining silicon oxide may be formed as a first insulating layer 749,a layer containing a resin may be formed as a second insulating layer750, and a layer containing silicon nitride may be formed as a thirdinsulating layer 751.

Note that a heat treatment for recovering crystallinity of thesemiconductor layers, activating the impurity elements added to thesemiconductor layers, or hydrogenating the semiconductor layers, ispreferably performed before forming the insulating layers 749 to 751 orafter forming one or a plurality of the insulating layers 749 to 751.The heat treatment may be a thermal annealing method, a laser annealingmethod, an RTA method, or the like.

Next, the insulating layers 749 to 751 are etched by a photolithographymethod to form opening portions which expose the second impurity regions726, 728, 730, 732 and the impurity region 785. Subsequently, aconductive layer is formed to fill the opening portion as shown in FIG.3A. The conductive layer is patterned to form conductive layers 752 to761 functioning as source and drain wirings.

The conductive layers 752 to 761 are formed by a CVD method, asputtering method, or the like with a single layer or a laminated layerof an element such as titanium (Ti), aluminum (Al), or neodymium (Nd),or an alloy material or a compound material containing such an elementas its main component. The alloy material containing aluminum as itsmain component corresponds to, for example, a material containingaluminum as its component and nickel, a material containing aluminum asits component and silicon, or a material containing aluminum as itscomponent and one or more of nickel, carbon and silicon. The conductivelayers 752 to 761 may have, for example, a laminated structure of abarrier layer, an aluminum layer containing silicon, and a barrier layeror a laminated structure of a barrier layer, an aluminum layercontaining silicon, a titanium nitride (EN) layer, and a barrier layer.In addition, silicon contained aluminum silicon is contained at 0.1 wt %to 5 wt %. Note that the barrier layer corresponds to a thin film oftitanium, nitride of titanium, molybdenum, or nitride of molybdenum. Analuminum layer and an aluminum layer containing silicon have lowresistance and are inexpensive, which are optimum for materials of theconductive layers 752 to 761. When upper and lower barrier layers areprovided, generation of a hillock of aluminum or aluminum silicon can beprevented. By forming the barrier layer of titanium that is an elementhaving a high reducing property, even when a thin natural oxide film isformed on the crystalline semiconductor layer, the natural oxide filmcan be reduced, so that occurrence of defective connection between thecrystalline semiconductor layer and the barrier layer can be suppressed.

Next, an insulating layer 762 serving as a protective film is formed tocover the conductive layers 752 to 761 (FIG. 3B). The insulating layer762 is formed with a single layer or a laminated layer of an inorganicmaterial or an organic material (preferably epoxy resin) by an SOGmethod, a droplet discharge method, or the like. In addition, theinsulating layer 762 is preferably formed with a thickness of 0.75 μm to3 μm.

Subsequently, the insulating layer 762 is etched by a photolithographymethod to form opening holes which expose the conductive layers 757,759, and 761. Then, a conductive layer is formed to fill the openingholes. The conductive layer is formed of a conductive material using aplasma CVD method, a sputtering method, or the like. Next, theconductive layer is patterned to form conductive layers 763, 764, 765connected to the conductive layers 757, 759, 761 respectively. Note thateach of the conductive layers 763 and 764 serves as one of a pair ofconductive layers included in a storage element portion. Consequently,the conductive layers 763 to 765 are preferably formed with a singlelayer or a laminated layer of titanium or an alloy material or acompound material containing titanium as its main component. Titaniumhas low resistance, which leads to a reduction in size of the storageelement portion and achievement of higher integration. In aphotolithography process to form the conductive layers 763 to 765, wetetching processing is preferably performed so as not to damage the thinfilm transistors 744 to 748 therebelow, and hydrogen fluoride (HF) orammonia-peroxide solution is preferably used as an etching agent(etchant).

Next, an insulating layer 766 is formed to cover the conductive layers763 to 765. The insulating layer 766 is formed with a single layer or alaminated layer of an inorganic material or an organic material by anSOG method, a droplet discharge method, or the like. The insulatinglayer 766 is preferably formed with a thickness of 0.75 μm to 3 μm.Subsequently, the insulating layer 766 is etched by a photolithographymethod to form opening portions 767 to 769 which expose the conductivelayers 763 to 765.

Next, a conductive layer 786 functioning as an antenna is formed incontact with the conductive layer 765 (see FIG. 4A). The conductivelayer 786 is formed of a conductive material by a CVD method, asputtering method, a printing method, a droplet discharge method, or thelike. Preferably, the conductive layer 786 is formed with a single layeror a laminated layer of an element such as aluminum (Al), titanium (Ti),silver (Ag), or copper (Cu), or an alloy material or a compound materialcontaining such an element as its main component. Specifically, analuminum layer is formed by a sputtering method and patterned to formthe conductive layer 786. The aluminum layer may be patterned by wetetching processing, and after the wet etching, a heat treatment may beperformed at a temperature of 200° C. to 300° C.

Next, an organic compound-containing layer 787 is formed to be incontact with the conductive layers 763 and 764 (FIG. 4B). The organiccompound-containing layer 787 is formed by a droplet discharge method,an evaporation method, or the like. Subsequently, a conductive layer 771is formed to be in contact with the organic compound-containing layer787. The conductive layer 771 is formed by a sputtering method, anevaporation method, or the like.

As an organic material used for the organic compound-containing layer,for example, an aromatic amine-based compound (that is, a compoundhaving a benzene ring-nitrogen bond) such as4,4′-bis[N-(1-naphthyl)-N-phenylanimo]biphenyl (abbreviation: α-NPD),4,4′-bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (abbreviation: TPD),4,4′,4″-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine(abbreviation: MTDATA), and4,4′-bis(N-{4-[N′-(3-methylphenyl)-N′-phenylamino]phenyl}-N-phenylamino)biphenyl(abbreviation: DNTPD), polyvinyl carbazole (abbreviation PVK), aphthalocyanine compound such as phthalocyanine (abbreviation: H₂Pc),copper phthalocyanine (abbreviation: CuPc), or vanadyl phthalocyanine(abbreviation: VOPc), or the like can be used. These materials have highhole transporting properties.

Besides, a material formed of a metal complex or the like having aquinoline skeleton or a benzoquinoline skeleton such astris(8-quinolinolato)aluminum (abbreviation: Alq₃),tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq₃),bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviation BeBq₂), orbis(2-methyl-8-quinolinolato)-4-phenylphenolato-aluminum (abbreviation:BAlq), a material formed of a metal complex or the like having anoxazole-based or thiazole-based ligand such asbis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: Zn(BOX)₂), orbis[2-(2-hydroxyphenyl)benzothiazolato]zinc (abbreviation: Zn(BTZ)₂), orthe like can be used. These materials have high electron transportingproperties.

Other than the metal complexes, a compound or the like such as2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation:PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene(abbreviation: OXD-7),3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: TAZ),3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen),bathocuproin (abbreviation: BCP), or the like can be used.

The memory material layer may have a single-layer structure or alaminated structure. In the case of a laminated structure, materials canbe selected from the aforementioned materials to form a laminatedstructure. Further, the aforementioned organic material and a lightemitting material may be laminated. As the light emitting material,4-dicyanomethylene-2-methyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran(abbreviation DOT),4-dicyanomethylene-2-t-butyl-6-[2-(1,1,7,7-tetramethyljulolidin-9-yl)ethenyl]-4H-pyran,periflanthene,2,5-dicyano-1,4-bis[2-(10-methoxy-1,1,7,7-tetramethyljulolidin-9-yl)ethenyl]benzene,N,N′-dimethylquinacridone (abbreviation DMQd), coumarin 6, coumarin545T, tris(8-quinolinolato)aluminum (abbreviation Alq₃), 9,9′-bianthryl,9,10-diphenylanthracene (abbreviation: DPA),9,10-bis(2-naphthyl)anthracene (abbreviation: DNA),2,5,8,11-tetra-t-buthylperylene (abbreviation: TBP), or the like can beused.

A layer in which the above light emitting material is dispersed may beused. In the layer in which the above light emitting material isdispersed, an anthracene derivative such as9,10-di(2-naphthyl)-2-tert-butylanthracene (abbreviation: t-BuDNA), acarbazole derivative such as 4,4′-di(N-carbazolyl)biphenyl(abbreviation: CBP), a metal complex such asbis[2-(2-hydroxyphenyl)pyridinato]zinc (abbreviation: Znpp₂) orbis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: ZnBOX), or thelike can be used as a base material. In addition,tris(8-quinolinolato)aluminum (abbreviation: Alq₃),9,10-bis(2-naphthyl)anthracene (abbreviation DNA),bis(2-methyl-8-quinolinolato)-4-phenylphenolato-aluminum (abbreviation:BAlq), or the like can be used.

The property of such an organic material is changed by a thermal effector the like; therefore, a glass transition temperature (Tg) thereof ispreferably 50° C. to 300° C., more preferably, 80° C. to 120° C.

In addition, a material in which metal oxide is mixed with an organicmaterial or a light emitting material may be used. Note that thematerial in which metal oxide is mixed includes a state in which metaloxide is mixed or stacked with the above organic material or the abovelight emitting material. Specifically, it indicates a state which isformed by a co-evaporation method using plural evaporation sources. Sucha material can be referred to as an organic-inorganic compositematerial.

For example, in the case of mixing a substance having a high holetransporting property with metal oxide, it is preferable to use vanadiumoxide, molybdenum oxide, niobium oxide, rhenium oxide, tungsten oxide,ruthenium oxide, titanium oxide, chromium oxide, zirconium oxide,hafnium oxide, or tantalum oxide as the metal oxide.

In the case of mixing a substance having a high electron transportingproperty with metal oxide, it is preferable to use lithium oxide,calcium oxide, sodium oxide, potassium oxide, or magnesium oxide as themetal oxide.

A material of which property changes by an electrical effect, an opticaleffect, or a thermal effect may be used for the memory material layer;therefore, for example, a conjugated high molecular compound doped witha compound (photoacid generator) which generates acid by absorbing lightcan also be used. As the conjugated high molecular compound,polyacetylenes, polyphenylene vinylenes, polythiophenes, polyanilines,polyphenylene ethinylenes, or the like can be used. As the photoacidgenerator, aryl sulfonium salt, aryl iodonium salt, o-nitrobenzyltosylate, aryl sulfonic acid p-nitrobenzyl ester, sulfonylacetophenones, Fe-arene complex PF6 salt, or the like can be used.

Note that the example of using an organic compound material for thestorage element portions 789 and 790 is described here, but the presentinvention is not limited thereto. For example, a phase change materialsuch as a material which changes reversibly between a crystalline stateand an amorphous state or a material which changes reversibly between afirst crystalline state and a second crystalline state can be used.Further, a material which changes only from an amorphous state to acrystalline state can be used.

The material which reversibly changes between a crystalline state and anamorphous state is a material containing a plurality of elementsselected from the group consisting of germanium (Ge), tellurium (Te),antimony (Sb), sulphur (S), tellurium oxide (TeOx), tin (Sn), gold (Au),gallium (Ga), selenium (Se), indium (In), thallium (Tl), cobalt (Co),and silver (Ag). For example, a material based on Ge—Te—Sb—S,Te—TeO₂—Ge—Sn, Te—Ge—Sn—Au, Ge—Te—Sn, Sn—Se—Te, Sb—Se—Te, Sb—Se,Ga—Se—Te, Ga—Se—Te—Ge, In—Se, In—Se—Tl—Co, Ge—Sb—Te, In—Se—Te, orAg—In—Sb—Te may be used. The material which reversibly changes betweenthe first crystalline state and the second crystalline state is amaterial containing a plurality of elements selected from the groupconsisting of silver (Ag), zinc (Zn), copper (Cu), aluminum (Al), nickel(Ni), indium (In), antimony (Sb), selenium (Se), and tellurium (Te), forexample, Ag—Zn, Cu—Al—Ni, In—Sb, In—Sb—Se, In—Sb—Te. When using such amaterial, a phase change is carried out between two differentcrystalline states. The material which changes only from an amorphousstate to a crystalline state is a material containing a plurality ofelements selected from the group consisting of tellurium (Te), telluriumoxide (TeO_(x)), palladium (Pd), antimony (Sb), selenium (Se), andbismuth (Bi), for example, Te—TeO₂, Te—TeO₂—Pd, or Sb₂Se₃/Bi₂Te₃.

Through the above described steps, the storage element portions 789, 790are completed. The storage element portion 789 has a laminated structureof the conductive layer 763, the organic compound-containing layer 787and the conductive layer 771, and the storage element portion 790 has alaminated structure of the conductive layer 764, the organiccompound-containing layer 787 and the conductive layer 771 (FIG. 4B).

Then, an insulating layer 772 serving as a substrate for protection isformed so as to cover the storage element portions 789, 790 and theconductive layer 786 serving as an antenna (FIG. 4B). The insulatinglayer 772 can be formed using any material as long as it has a functionof preventing a layer including a TFT from being damaged in a separationstep described later, without particular limitation; however, theinsulating layer 772 is preferably formed using resin (more preferablyepoxy resin). Epoxy resin is used as the insulating layer 772 to improveplanarity on the surface of the insulating layer 772, reduce damages tothe layer including a TFT in the later separation step, protect thestorage element portion and the element formation layer below theinsulating layer 772 from dusts and the like, and keep the mechanicalstrength of the semiconductor device. In the semiconductor device ofthis embodiment mode, the insulating layer 772 can be used as asubstrate covering the conductive layer 786 serving as an antenna. Thus,a semiconductor device which is thin and bendable can be provided.Furthermore, in this embodiment mode, the insulating layer 772 may beformed such that the ratio of the thickness of the insulating layer 772in a portion not covering the conductive layer 786 to the thickness ofthe conductive layer 786 serving as an antenna is at least 1.2, and theratio of the thickness of the insulating layer 772 formed over theconductive layer 786 serving as an antenna to the thickness of theconductive layer 786 is at least 0.2. As a result, it is possible thatthe surface of the insulating layer 772 has planarity enough to reducedamages to the element formation layer in the manufacturing process ofthe semiconductor device, and thus, a semiconductor device havingmechanical strength enough to protect the storage element portion andthe element formation layer can be provided.

It is to be noted that in this embodiment mode, the layer including thethin film transistors 744 to 748 and the conductive layers 752 to 761 isreferred to as an element formation layer 791, and the layer includingthe storage element portions 789, 790 and the conductive layer 786serving as an antenna is referred to as a region 792. Preferably, thethickness of the layers below the conductive layer 786 serving as anantenna, excluding the substrate 701, is 5 μm or less, preferably 0.1 μmto 3 μm. Although not shown here, in the element formation layer 791,elements such as a diode, a TFT, a capacitor, and a resistor whichconstitute the memory section 202 and the integrated circuit portion 201are formed.

Then, the insulating layers 703, 749, 750, 751 and 772 are etched by adicer, a laser, a wire saw or the like, so as to expose a part of thesurface of the separation layer 702, thereby forming opening portions773 and 774 (see FIG. 5A).

Next, an etching agent is introduced into the opening portions 773, 774to remove the separation layer 702 (FIG. 5A). As the etching agent, agas or a liquid containing halogen fluoride is used. For example,chlorine trifluoride (ClF₃), nitrogen trifluoride (NF₃), brominetrifluoride (BrF₃), and hydrogen fluoride (HF) are given. Note that whenhydrogen fluoride is used as the etching agent, a layer includingsilicon oxide is used as the separation layer 702. The layer includingthe thin film transistors 744 to 748 is separated from the firstsubstrate 701.

The first substrate 701 from which the element formation layer 791including the thin film transistors 744 to 748 is separated may bereused for the sake of cost reduction. In addition, the insulating layer772 is provided so that the element formation layer 791 is not strippedafter the separation layer 702 is removed. Since the element formationlayer 791 is thin and light, the element formation layer 791 is notattached closely to the first substrate 701 and thus, easy to bestripped after the separation layer 702 is removed. However, theinsulating layer 722 is formed over the element formation layer 791 toincrease the weight of the element formation layer 791, therebypreventing the element formation layer 791 from being scattered from thefirst substrate 701. In addition, the element formation layer 791 itselfis thin and light; however, as the result of forming the insulatinglayer 772, the element formation layer 791 is not warped and thus, canhave a certain level of strength.

Next, the insulating layer 772 is bonded to a sheet member 776 to becompletely separated from the first substrate 701 (see FIG. 5B). Here,the sheet member 776 may be a material which has high adhesiveness in anormal state but low adhesiveness when it is applied with heat andirradiated with light. For example, a heat-peeling tape whoseadhesiveness is weakened by heat, a UV-peeling tape whose adhesivenessis weakened by ultraviolet rays, or the like may be used. In addition, alow-viscosity tape having low adhesiveness in a normal state may beused, for example.

Next, a second substrate 778 is fixed on the insulating layer 703. Here,the second substrate 778 corresponds to a film obtained by stacking anadhesive synthetic resin film (e.g., acrylic synthetic resin orepoxy-based synthetic resin) and any of a film made of polypropylene,polyester, vinyl, polyvinyl fluoride, vinyl chloride, or the like; papermade of a fibrous material; and a base film (e.g., polyester, polyamide,inorganic deposited film, or paper). Preferably, the thickness of thesecond substrate 778 is in the range of about 2 μm to 20 μm. With theuse of the second substrate 778 made of plastic, a device using thesecond substrate 778 is thin, light, and bendable, which leads to theuse for various designs and easy processing into a flexible shape. Sucha device has a high-impact resistance, and is easy to be attached orembedded into various goods, which allows application to wide variety offields.

In this embodiment mode, an adhesive layer is provided for the surfaceof the second substrate 778, on the insulating layer 703 side. Theadhesive layer corresponds to a layer including an adhesive such as aheat curing resin, an ultraviolet curing resin, a vinyl acetateresin-based adhesive, a vinyl copolymer resin-based adhesive, an epoxyresin-based adhesive, an urethane resin-based adhesive, a rubber-basedadhesive, or an acrylic resin-based adhesive.

In this embodiment mode, a thick support 779 having a larger thicknessthan the second substrate 778 is provided for the surface of the secondsubstrate 778, not on the insulating layer 703 side. In this embodimentmode, since the second substrate 778 has a small thickness of about 2 μmto 20 μm is difficult to be handled. However, the support 779 isprovided for the second substrate 778 so that the second substrate 778can be easily handled. Note that the support 779 is removed at the endof the process. In this embodiment mode, the second substrate 778 hasthe support 779, so that a substrate having extremely thin thickness canbe used as the second substrate 778.

Note that the surface of the second substrate 778 may be coated withsilicon dioxide (silica) powder. The coating allows the surface to bekept water-resistant even in an environment of high temperature and highhumidity. Moreover, the surface may be coated with a conductive materialsuch as indium tin oxide, so that the material coating the surfacecharges static electricity, and thus a thin film integrated circuit canbe protected from static electricity. The surface may also be coatedwith a material containing carbon as its main component (such as diamondlike carbon). The coating increases the strength and can prevent thedegradation or destruction of a semiconductor device.

Next, the substrate 778 including the element formation layer 791 andthe sheet member 776 are separated from each other. Here, a UV-peelingtape is used as the sheet member 776. First, the sheet member 776 isirradiated with ultraviolet rays to weaken the adhesiveness between thesheet member 776 and the insulating layer 772 (FIG. 6). Then, the sheetmember 776 is separated from the insulating layer 772. Then, the support779 provided for the second substrate 778 is separated from the secondsubstrate 778.

Through the above steps, a semiconductor device shown in FIG. 1B can bemanufactured.

The antenna 203 shown in FIGS. 1A and 1B may be provided so as tooverlap with the memory section 202 or in the periphery of the memorysection 202, not overlapping with it. When the antenna 203 overlaps withthe memory section 202, it may overlap with the entire surface or a partthereof.

As a method for wirelessly transmitting signals by the semiconductordevice 200, an electromagnetic coupling method, an electromagneticinduction method, a microwave method, or the like can be used. Thetransmission method may be selected as appropriate in consideration ofthe purpose by a practitioner, and a suitable antenna may be provided inaccordance with the transmission method.

In the case of using an electromagnetic coupling method or anelectromagnetic induction method (for example, 13.56 MHz band) utilizingelectromagnetic induction caused by the change in magnetic fielddensity, a conductive layer functioning as an antenna is formed in aloop shape (such as a loop antenna) or a spiral shape (such as a spiralantenna).

In the case of using a microwave method (for example, UHF band (860 to960 MHz band), 2.45 GHz band, or the like), the shape of a conductivelayer functioning as an antenna, such as the length, may be asappropriate set in consideration of the wavelength of an electromagneticwave used for the signal transmission. For example, the conductive layerfunctioning as an antenna can be formed to have a linear shape (such asa dipole antenna), a flat shape (such as a patch antenna), or a ribbonshape. The shape of the conductive layer functioning as an antenna isnot limited to a linear shape but may be a curved shape, a meanderingshape, or a combination thereof in consideration of the wavelength of anelectromagnetic wave.

A TFT may have a single gate structure in which one channel formationregion is formed, a double gate structure in which two channel formationregions are formed, or a triple gate structure in which three channelformation regions are formed. That is, the present invention can beapplied to a TFT having a multi gate structure including a plurality ofchannel formation regions. Further, a thin film transistor in aperipheral driver circuit region may also have a single gate structureor a multi gate structure such as a double gate structure or a triplegate structure.

The present invention is not limited to a method for manufacturing theTFT described in this embodiment mode, but also applied to a method formanufacturing a TFT of a top gate type (planar type), a bottom gate type(reversely staggered type), a dual gate type having two gate electrodesarranged above and below a channel region with gate insulating layersinterposed therebetween, or other structures.

A semiconductor device of the present invention has at least one surfacecovered by a resin. Thus, in the semiconductor device, a storage elementportion and an element formation layer below the resin layer can beprotected from dusts and the like, and the mechanical strength of thesemiconductor device can be kept. Further, in the semiconductor deviceof the present invention, a resin layer is used as a substrate coveringat least one surface, and thus a semiconductor device which is thin andbendable can be provided. In addition, the insulating layer is formedover the conductive layer serving as an antenna such that the value inthickness ratio of the insulating layer in a portion not covering theconductive layer to the conductive layer is at least 1.2, and the valuein thickness ratio of the insulating layer formed over the conductivelayer to the conductive layer is at least 0.2. Thus, the surface of theinsulting layer has a sufficient planarity to reduce damages to anelement formation layer in a manufacturing process of a semiconductordevice. In addition, a semiconductor device having a mechanical strengthenough to protect the storage element portion and the element formationlayer can be provided. Further, the semiconductor device of the presentinvention may be formed such that a conductive layer is not exposed inthe side face of the semiconductor device, and an insulating layercovering a TFT and the conductive layer is exposed in the side face ofthe semiconductor device. Thus, elements such as a TFT or an antenna canbe protected from dusts and the like by only the insulating layercovering the conductive layer serving as antenna, and thus, thesemiconductor device which does not easily deteriorate can be provided.In addition, in a semiconductor device of the present invention, as asubstrate covering an element formation layer side, a substrate having asupport in its surface is used in the manufacturing process, and thus,the substrate having a thickness of 2 μm to 20 μm can be easily handled.Therefore, a semiconductor device which is thin and bendable can beeasily manufactured.

(Embodiment Mode 2)

Embodiment Mode 2 will describe a manufacturing process of asemiconductor device which is different from that of Embodiment Mode 1.Specifically, a process is described in which a pn junction of a memorycell and a thin film transistor of a logic portion for controlling thememory cell are formed at the same time.

FIG. 7 shows a schematic cross-sectional structure of a semiconductordevice of this embodiment mode. The semiconductor device of thisembodiment mode includes an antenna, a memory section, and an integratedcircuit portion. The cross section of the memory cell as a part of thememory section is shown in the center of FIG. 7. In the memory cell, astorage element portion is stacked over a diode as a part of the memorysection. The left part of the drawing shows a cross section of ap-channel TFT (also referred to as a p-ch TFT) and an n-channel TFT(also referred to as an n-ch TFT) as a part of the cross section of thelogic circuit in the memory section. The right part of the drawing showsa cross section of a part of the antenna 210, and further a capacitor ofthe resonance circuit 212 and an n-channel TFT of a high withstandvoltage type of the power source circuit 213 as a part of the crosssection of the integrated circuit portion, as shown in FIG. 12. It isneedless to say that the integrated circuit portion is also providedwith p-channel TFTs and n-channel TFTs similarly to the logic circuit onthe left part of the drawing, in addition to the TFT of a high withstandvoltage type. Moreover, naturally, the memory section and the integratedcircuit portion are provided with a plurality of TFTs and capacitorsshown in FIG. 7.

A substrate 260 is a substrate used when an element formation layer 250is formed. In this embodiment mode, a glass substrate is used as thesubstrate 260. A peeling layer 261 is formed over the substrate 260,which is used to remove the substrate 260 from the element formationlayer 250. The peeling layer 261 is formed over the substrate 260, and abase insulating layer 249 is formed thereover, and then the elementformation layer 250 including TFTs or the like is formed over the baseinsulating layer 249. A method for forming the semiconductor device ofthis embodiment mode is explained hereinafter with reference to FIG. 7to FIG. 11.

The substrate 260 is a glass substrate. As shown in FIG. 8A, the peelinglayer 261 including three layers 261 a to 261 c is formed over thesubstrate 260. The first layer 261 a is formed by a silicon oxynitridefilm (SiO_(x)N_(y), x>y) of 100 nm thick by a parallel plate type plasmaCVD apparatus using SiH₄ and N₂O as source gases. The second layer 261 bis formed by a tungsten film of 30 nm thick using a sputteringapparatus. The third layer 261 c is formed by a silicon oxide film of200 nm thick using a sputtering apparatus.

By the formation of the third layer 261 c (silicon oxide), a surface ofthe second layer 261 b (tungsten) is oxidized to form tungsten oxide atthe interface. By the tungsten oxide, the substrate 261 can be easilyseparated when the element formation layer 250 is transferred to anothersubstrate later. The first layer 261 a is a layer for increasing theadhesiveness of the second layer 261 b during the manufacturing of theelement formation layer 250.

The second layer 261 b is preferably formed by a metal film includingtungsten (W), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium(Nb), nickel (Ni), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium(Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or thelike or a film of a compound of such metal. The second layer 261 b canhave a thickness of 20 nm to 40 nm.

As shown in FIG. 8B, the base insulating layer 249 having a two-layerstructure is formed over the peeling layer 261. The first layer 249 a isformed of silicon oxynitride (SiO_(x)N_(y), x<y) in 50 nm thick by aplasma CVD apparatus using SiH₄, N₂O, NH₃, and H₂ as source gases. Thebarrier property is increased such that the composition ratio ofnitrogen of the first layer 249 a can be 40% or more. The second layer249 b is formed of silicon oxynitride (SiO_(x)N_(y), x>y) having athickness of 100 nm by a plasma CVD apparatus using SiH₄ and N₂O assource gases. The composition ratio of nitrogen of the second layer 249b is 0.5% or less.

As shown in FIG. 8C, a crystalline silicon film 271 is formed over thebase insulating layer 249. The crystalline silicon film 271 ismanufactured by the following method. An amorphous silicon film isformed having a thickness of 66 nm by a plasma CVD apparatus using SiH₄and H₂ as source gases. The amorphous silicon film is irradiated withlaser light so as to be crystallized; thus, the crystalline silicon film271 is formed. An example of a laser irradiation method is shown. Asecond harmonic (wavelength: 532 nm) of an LD-pumped YVO₄ laser is usedfor the irradiation. The laser is not especially limited to the secondharmonic, but the second harmonic is superior to third or higherharmonics in point of energy efficiency. The laser irradiation isconducted such that the beam on the irradiation surface has a linearshape with a length of about 500 μm and a width of about 20 μm and anintensity of 10 to 20 W by an optical system. The beam is moved relativeto the substrate at a speed of 10 to 50 cm/sec.

As shown in FIG. 8D, a p-type impurity is added to the crystallinesilicon film 271. Here, diborane (B₂H₆) diluted with hydrogen is used asa doping gas in an ion doping apparatus, so that boron is entirely addedto the crystalline silicon film 271. The crystalline silicon obtained bycrystallizing amorphous silicon has a dangling bond; therefore, it isnot ideal intrinsic silicon but has a low n-type conductivity.Accordingly, addition of a minute amount of p-type impurities providesan effect of making the amorphous silicon film 271 into intrinsicsilicon. The step in FIG. 8D may be conducted as necessary.

Next, as shown in FIG. 8E, the crystalline silicon film 271 is dividedfor each element to form semiconductor layers 272 to 276. In thesemiconductor layer 272, a diode of the memory cell is formed. By theuse of the semiconductor layers 273 to 275, channel formation regions,source regions, and drain regions of TFTs are formed. The semiconductorlayer 276 forms an electrode of an MIS capacitor. An example of a methodfor processing the crystalline silicon film 271 is shown. A resist isformed over the crystalline silicon film 271 by a photolithographyprocess, and the crystalline silicon film 271 is etched by using theresist as a mask and using SF₆ and O₂ as an etching agent with a dryetching apparatus; thus, the semiconductor layers 272 to 276 havingdesired shapes are formed.

As shown in FIG. 9A, a resist R31 is formed by a photolithographyprocess and a minute amount of p-type impurities is added to thesemiconductor layers 274 and 275 of the n-channel TFTs. Here, diborane(B₂H₆) diluted with hydrogen is used as a doping gas so that thesemiconductor layers 274 and 275 are doped with boron by an ion dopingapparatus. The resist R31 is removed after the completion of the doping.

The step in FIG. 9A is performed to prevent the threshold voltage of then-channel TFT from becoming negative. Boron may be added to thesemiconductor layers 274 and 275 of the n-channel TFTs at aconcentration of 5×10¹⁵ atoms/cm³ to 1×10¹⁷ atoms/cm³. The step in FIG.9A may be conducted as necessary. Moreover, the p-type impurity may beadded to the semiconductor layer 272 of the memory cell.

As shown in FIG. 9B, an insulating layer 277 is formed over the entiresurface of the substrate 260. The insulating layer 277 functions as agate insulating layer for the TFTs and a dielectric for the capacitor.Here, the insulating layer 277 is formed of a silicon oxynitride film(SiO_(x)N_(y), x>y) having a thickness of about 20 nm to 40 nm by aplasma CVD apparatus using SiH₄ and N₂O as source gases.

As shown in FIG. 9C, a resist R32 is formed by a photolithographyprocess, and an n-type impurity is added to the semiconductor layer 272of the memory cell and the semiconductor layer 276 of the capacitor. Bythis step, the concentration of the n-type impurity in each of then-type impurity region of the semiconductor layer 272 and the n-typeimpurity region functioning as one electrode of the capacitor isdetermined. Phosphine (PH₃) diluted with hydrogen is used as a dopinggas, so that the semiconductor layers 272 and 276 are doped withphosphorus by using an ion doping apparatus. Thus, the entiresemiconductor layer 272 becomes an n-type impurity region 278 and theentire semiconductor layer 276 becomes an n-type impurity region 279.The resist R32 is removed after the completion of the doping step.

As shown in FIG. 9D, a conductive layer 281 is formed over theinsulating layer 277. The conductive layer 281 forms a gate electrode ofthe TFT, or the like. Here, the conductive layer 281 has a two-layerstructure. The first layer is formed of tantalum nitride (TaN) with athickness of 30 nm and the second layer is formed of tungsten (W) with athickness of 370 nm. The tantalum nitride and the tungsten are formed bya sputtering apparatus.

A resist is formed over the conductive layer 281 by a photolithographyprocess, and the conductive layer 281 is etched by an etching apparatus.Thus, first conductive layers 283 to 286 are formed over thesemiconductor layers 273 to 275 and 279 as shown in FIG. 10A. The firstconductive layers 283 to 286 serve as gate electrodes or gate wires ofthe TFTs. In the n-channel TFT of a high withstand voltage type, theconductive layer 285 is formed so that the gate width (channel length)is larger than that in the other TFTs. The first conductive layer 286forms one electrode of the capacitor.

The conductive layer 281 is etched by a dry etching method. As anetching apparatus, an ICP (Inductively Coupled Plasma) etching apparatusis used. As an etching agent, a mixed gas of Cl₂, SF₆, and O₂ is usedfirst in order to etch the tungsten, and then the etching agent to beintroduced in a process chamber is changed to only a Cl₂ gas to etch thetantalum nitride.

As shown in FIG. 10B, a resist R33 is formed by a photolithographyprocess. An n-type impurity is added to the semiconductor layers 274 and275 of the n-channel TFT. N-type low-concentration impurity regions 288and 289 are formed in a self-aligning manner in the semiconductor layer274 by using the first conductive layer 284 as a mask, and n-typelow-concentration impurity regions 290 and 291 are formed in aself-aligning manner in the semiconductor layer 275 by using the firstconductive layer 285 as a mask. In this embodiment mode, phosphine (PH₃)diluted with hydrogen is used as a doping gas, and phosphorus is addedto the semiconductor layers 274 and 275 by an ion doping apparatus. Thestep of FIG. 10B is a step of forming an LDD region in the n-channelTFT. The n-type impurity is included in the n-type low-concentrationimpurity regions 288 and 289 at a concentration of 1×10¹⁶ atoms/cm³ to5×10¹⁸ atoms/cm³.

As shown in FIG. 10C, a resist R34 is formed by a photolithographyprocess. A p-type impurity is added to the semiconductor layer 278 ofthe memory cell and the semiconductor layer 273 of the p-channel TFT.Since a part of the semiconductor layer 278 which is left as an n-typeimpurity region 278 n is covered with the resist R34, an exposed region278 p becomes a p-type impurity region. By this impurity addition step,the n-type impurity region 278 n and the p-type impurity region 278 pforming a pn junction are formed in the semiconductor layer 278. Sincethe semiconductor layer 278 is formed in advance as the n-type impurityregion, the p-type impurity is added at higher concentration than then-type impurity added in advance so that the region 278 p can havep-type conductivity.

P-type high-concentration impurity regions 273 a and 273 b are formed ina self-aligning manner in the semiconductor layer 273 by using the firstconductive layer 283 as a mask. A region 273 c covered with the firstconductive layer 283 is formed in a self-aligning manner as the channelformation region.

The p-type impurity regions are formed by doping the semiconductorlayers 274 and 275 with boron by an ion doping apparatus using diborane(B₂H₆) diluted with hydrogen as a doping gas. The resist R34 is removedafter the completion of the doping.

As shown in FIG. 10D, insulating layers 293 to 296 are formed in theperipheries of the first conductive layers 283 to 286. The insulatinglayers 293 to 296 are called sidewalls or side walls. First, a siliconoxynitride film (SiO_(x)N_(y), x>y) is formed to be 100 nm thick by aplasma CVD apparatus using SiH₄ and N₂O as source gases. Subsequently, asilicon oxide film is formed to be 200 nm thick by an LPCVD apparatususing SiH₄ and N₂O as source gases. A resist is formed by aphotolithography process. By using this resist, the silicon oxide layerin the upper layer is subjected to wet-etching by buffered hydrochloricacid, then the resist is remove, and the silicon nitride oxide film inthe lower layer is subjected to dry etching, thereby forming theinsulating layers 293 to 296. In accordance with a sequence of thesesteps, the insulating layer 277 formed of silicon oxynitride is alsoetched and the insulating layer 277 is left only under the firstconductive layers 283 to 286 and the insulating layers 293 to 296.

As shown in FIG. 11A, a resist R35 is formed by a photolithographyprocess. An n-type impurity is added to the semiconductor layers 274 and275 of the n-channel TFTs and the semiconductor layer of the capacitor,thereby forming n-type high-concentration impurity regions. In thesemiconductor layer 274, the n-type impurity is further added to then-type low-concentration impurity regions 288 and 289 (see FIG. 10B) byusing the first conductive layer 284 and the insulating layer 294 asmasks, thereby forming n-type high-concentration impurity regions 274 aand 274 b in a self-aligning manner. A region 274 c overlapping with thefirst conductive layer 284 becomes a channel formation region in aself-aligning manner. In addition, regions 274 e, 274 d of the n-typelow-concentration impurity regions 288 and 289 that overlap with theinsulating layer 294 are left as n-type low-concentration impurityregions.

Similarly to the semiconductor layer 274, n-type high-concentrationimpurity regions 275 a and 275 b, a channel formation region 275 c, andn-type low-concentration impurity regions 275 e and 275 d are formed inthe semiconductor layer 275.

At this time, the entire semiconductor layer 279 becomes the n-typeimpurity region (see FIG. 9C). An n-type impurity is further added tothe n-type impurity region 279 by using the first conductive layer 286and the insulating layer 296 as masks, thereby forming n-typehigh-concentration impurity regions 279 a and 279 b in a self-aligningmanner. A region of the semiconductor layer 279 that overlaps with thefirst conductive layer 286 and the insulating layer 296 is an n-typeimpurity region 279 c.

In the step of adding the n-type impurity, as aforementioned, an iondoping apparatus may be used and phosphine (PH₃) diluted with hydrogenmay be used as a doping gas. The n-type high-concentration impurityregions 274 a, 274 b, 275 a, and 275 b of the n-channel TFTs are dopedwith phosphorus so that the concentration of phosphorus ranges from1×10²⁰ atoms/cm³ to 2×10²¹ atoms/cm³.

As mentioned above, in this embodiment mode, the n-type impurity region278 n and the p-type impurity region 278 p of the memory cell are formedin accordance with a sequence of steps of adding impurities to thesemiconductor layers for the thin film transistors and the capacitor. Inthis embodiment mode, the concentration of the n-type impurity and thep-type impurity is the same in the n-type impurity region 278 n and then-type high-concentration impurity region 279 c of the capacitor. Thus,their sheet resistances are the same. The p-type impurity region 278 phas the same concentration of the p-type impurity as the p-typehigh-concentration impurity regions 273 a and 273 b of the p-channelthin film transistor; however, the p-type impurity region 278 p hashigher concentration of the n-type impurity than the p-typehigh-concentration impurity regions 273 a and 273 b. Moreover, thep-type impurity region 278 p has the same concentration of the n-typeimpurity as the n-type impurity region 279 c of the capacitor.

The resist R35 is removed to form a cap insulating layer 298 as shown inFIG. 11B. The cap insulating layer 298 is formed by a silicon oxynitridefilm (SiO_(x)N_(y), x>y) in 50 nm thick by a plasma CVD apparatus. SiH₄and N₂O are used as source gases to form the silicon oxynitride film.After forming the cap insulating layer 298, a heat treatment isperformed in a nitrogenous atmosphere of 550° C. to activate the n-typeimpurity and the p-type impurity added to the semiconductor layers 273to 275 and 278 to 279.

As shown in FIG. 11C, first interlayer insulating layers 299 and 300 areformed. The first interlayer insulating layer 299 as a first layer isformed of silicon oxynitride (SiO_(x)N_(y), x<y) having a thickness of100 nm by a plasma CVD apparatus using SiH₄ and N₂O as source gases. Thefirst interlayer insulating layer 300 as a second layer is formed ofsilicon oxynitride (SiO_(x)N_(y), x>y) having a thickness of 600 nm byusing SiH₄, N₂O, NH₃, and H₂ as source gases by a plasma CVD apparatus.

The first interlayer insulating layer 299 and 300 and the cap insulatinglayer 298 are removed by a photolithography process and a dry etchingprocess, thereby forming contact holes. A conductive layer is formedover the first interlayer insulating layer 300. Here, the conductivelayer has a four-layer structure in which Ti of 60 nm thick, TiN of 40nm thick, pure aluminum of 500 nm thick, and Ti of 100 nm thick arestacked in order from the bottom. These layers are formed by asputtering apparatus. The conductive layer is processed into apredetermined shape by a photolithography process and a dry etchingprocess, thereby forming second conductive layers 301 to 315.

Although the second conductive layers and the first conductive layer areconnected to each other over the semiconductor layer in the drawing inorder to explain the connection between the second conductive layers andthe first conductive layer. Actually, the second conductive layers andthe first conductive layer may be formed so that the contact portiontherebetween does not overlap with the semiconductor layer.

The second conductive layer 301 of the memory cell forms a word line.The second conductive layer 302 forms an electrode for connecting thediode with the storage element and is divided for each memory cell. Then-type high-concentration impurity regions 279 a and 279 b are connectedto each other by the second conductive layer 312. Accordingly, an MIScapacitor of a stacked-layer structure including the n-type impurityregion 279 c, the insulating layer 277, and the first conductive layer286 is formed. The second conductive layer 314 forms a terminal of theintegrated circuit portion, to which the antenna 210 is connected.

Then, through the steps similar to those in Embodiment Mode 1, thesemiconductor device as shown in FIG. 7 can be provided. In other words,an insulating layer 762 is formed over the second conductive layers 301to 315, conductive layers 764, 765 are formed over the insulating layer762 and in contact holes, an insulating layer 766 is formed over theconductive layers 764, 765, an organic compound-containing layer 787 isformed to partially cover the insulating layer 766 and the conductivelayer 764, a conductive layer 771 is formed over the organiccompound-containing layer 787, a conductive layer 786 serving as anantenna is formed over the conductive layer 765, and an insulating layer772 is formed over the conductive layers 771 and 786.

Although the semiconductor layer 276 of the capacitor has the n-typeimpurity region, it may also have a p-type impurity region. In thelatter case, a p-type impurity is added in the step of FIG. 9C. In thestep of FIG. 9C, the entire semiconductor layer 278 of the memory cellbecomes a p-type impurity region. Therefore, in the step of FIG. 10C,the p-type impurity is not added to the semiconductor layer 278. Then,the n-type impurity is added to a predetermined region of thesemiconductor layer 278 in the step of FIG. 11A.

A semiconductor device of the present invention has at least one surfacecovered by a resin. Thus, in the semiconductor device, a storage elementportion and an element formation layer below the resin layer can beprotected from dusts and the like, and the mechanical strength of thesemiconductor device can be kept. Further, in the semiconductor deviceof the present invention, a resin layer is used as a substrate coveringat least one surface, and thus a semiconductor device which is thin andbendable can be provided. In addition, the insulating layer is formedover the conductive layer serving as an antenna such that the value inthickness ratio of the insulating layer in a portion not covering theconductive layer to the conductive layer is at least 1.2, and the valuein thickness ratio of the insulating layer formed over the conductivelayer to the conductive layer is at least 0.2. Thus, the surface of theinsulting layer has a sufficient planarity to reduce damages to anelement formation layer in a manufacturing process of a semiconductordevice. In addition, a semiconductor device having a mechanical strengthenough to protect the storage element portion and the element formationlayer can be provided. Further, the semiconductor device of the presentinvention may be formed such that a conductive layer is not exposed inthe side face of the semiconductor device, and an insulating layercovering a TFT and the conductive layer is exposed in the side face ofthe semiconductor device. Thus, elements such as a TFT or an antenna canbe protected from dusts and the like by only the insulating layercovering the conductive layer serving as antenna, and thus, thesemiconductor device which does not easily deteriorate can be provided.In addition, in a semiconductor device of the present invention, as asubstrate covering an element formation layer side, a substrate having asupport in its surface is used in the manufacturing process, and thus,the substrate having a thickness of 2 μm to 20 μm can be easily handled.Therefore, a semiconductor device which is thin and bendable can beeasily manufactured.

Moreover, the semiconductor device of this embodiment mode has a pnjunction in the memory cell, and thus, can write data in the storageelement portion using an organic material, at any time including themanufacturing time. Therefore, the semiconductor device shown in thisembodiment mode is applied to high value-added semiconductor devicessuch as wireless chips, which leads to cost reduction.

The pn junction in the memory cell shown in this embodiment mode can beformed at the same time as thin film transistors of a logic circuitcontrolling the memory cell, as well as can be formed without specialsteps added to the manufacturing process of the thin film transistors.Therefore, conventional resources and facilities for forming thin filmtransistors can be used as they are, and the present invention isindustrially very effective.

(Embodiment Mode 3)

Embodiment Mode 3 will explain an example of applying a semiconductordevice of the present invention to a semiconductor device capable ofinputting and outputting data without contact with reference todrawings. The semiconductor device capable of inputting and outputtingdata without contact is also referred to as an RFID (Radio FrequencyIdentification) tag, an ID tag, an IC tag, an IC chip, an RF tag, awireless tag, an electronic tag, or a wireless chip.

FIG. 12 is a block diagram showing a structure example of asemiconductor device 200 of this embodiment mode. The semiconductordevice 200 has an antenna 210 to exchange data without contact(wirelessly). The semiconductor device 200 further includes a resonancecircuit 212, a power source circuit 213, a reset circuit 214, a clockgenerating circuit 215, a data demodulating circuit 216, a datamodulating circuit 217, a control circuit 220 for controlling anothercircuit, and a memory section 230, as signal processing circuits whichprocess signals received with the antenna and supply signals fortransmission to the antenna.

The resonance circuit 212 is a circuit in which a capacitor and a coilare connected to each other in parallel, and which receives a signalwith the antenna 210 and outputs from the antenna 210 a signal receivedfrom the data modulating circuit 217. The power source circuit 213 is acircuit for generating a power source potential based on a receivedsignal. The reset circuit 214 is a circuit for generating a resetsignal. The clock generating circuit 215 is a circuit for generatingvarious clock signals based on a received signal inputted through theantenna 210. The data demodulating circuit 216 is a circuit fordemodulating a received signal and outputting the demodulated signal tothe control circuit 220. The data modulating circuit 217 is a circuitfor modulating a signal received from the control circuit 220.

The memory section 230 can have, for example, a structure example shownin FIG. 13A. The memory section 230 shown in this embodiment modeincludes the following over a substrate 10: a memory cell array 11having memory cells arranged in matrix; decoders 12, 13, a selector 14,a read-write circuit 15, and the like. The memory cell array 11 hasmemory cells of n rows×m columns. The decoder 13 is connected to thememory cell array 11 by n number of word lines Wh (h=1, 2, . . . n), andthe selector 14 is connected to the memory cell array 11 by m number ofbit lines Bk (k=1, 2, . . . m). The structure of the memory sectionshown in FIG. 13A is only an example, and the memory section may furtherinclude another circuit such as a sense amplifier, an output circuit, ora buffer over the substrate 10.

FIG. 13B shows an example of an equivalent circuit diagram of a memorycell MC provided in the memory cell array 11. FIG. 13B shows memorycells MCs of 3 rows×3 columns. In this embodiment mode, each memory cellMC includes a storage element portion MD and a diode DI connectedserially to the storage element portion MD. The storage element portionMD is connected to the bit line Bk and the diode DI is connected to theword line Wh. The diode DI can be connected in the opposite direction,in other words, the diode DI can be connected to the storage elementportion MD by a terminal opposite to the terminal shown in FIG. 13B. Therelation between the bit line B and the word line W may be opposite.Note that the structure of the memory section 230 is not limited to thestructures shown in FIGS. 13A and 13B.

As the control circuit 220, for example, a code extracting circuit 221,a code judging circuit 222, a CRC judging circuit 223, and an outputunit circuit 224 are provided. The code extracting circuit 221 is acircuit for extracting each of a plurality of codes included in aninstruction transmitted to the control circuit 220. The code judgingcircuit 222 is a circuit for judging the content of the instruction bycomparing the extracted code and a code corresponding to a reference.The CRC judging circuit 223 is a circuit for detecting whether there isa transmission error or the like based on the judged code.

Next, an example of an operation of the semiconductor device 200 isexplained. After receiving a wireless signal with the antenna 210, thewireless signal is transmitted to the power source circuit 213 via theresonance circuit 212, thereby generating a high power source potential(hereinafter referred to as a VDD). The VDD is supplied to the circuitsin the semiconductor device 200. The signal transmitted to the datademodulating circuit 216 via the resonance circuit 212 is demodulated(hereinafter referred to as a demodulation signal). Moreover, thesignals passed through the reset circuit 214 and the clock generatingcircuit 215 via the resonance circuit 212 and the demodulation signalare transmitted to the control circuit 220. The signals transmitted tothe control circuit 220 are analyzed by the code extracting circuit 221,the code judging circuit 222, the CRC judging circuit 223, and the like.The information of the semiconductor device stored in the memory section230 is outputted in accordance with the analyzed signals. The outputtedinformation of the semiconductor device is encoded through the outputunit circuit 224. The encoded information of the semiconductor device200 is transmitted as a wireless signal by the antenna 210 through thedata modulating circuit 217. In the plural circuits of the semiconductordevice 200, a low power source potential (hereinafter referred to asVSS) is common, and the VSS can be GND.

Thus, the data of the semiconductor device can be read by transmitting asignal from a reader/writer to the semiconductor device 200 andreceiving the signal transmitted from the semiconductor device 200 bythe reader/writer.

The semiconductor device 200 can supply a power source voltage to eachcircuit by an electromagnetic wave without mounting a power source(battery). Alternatively, the semiconductor device 200 can have a powersource (battery) mounted to supply a power source voltage to eachcircuit by an electromagnetic wave and the power source (battery).

Subsequently, an example of an application of a semiconductor devicewhich can input and output data without contact (or wirelessly) isexplained with reference to FIGS. 14A and 14B. A side face of a portableterminal including a display portion 321 is provided with areader/writer 320, and a side face of a product 322 is provided with anRFID tag 323 (FIG. 14A). When the reader/writer 3200 is held over theRFID tag 323 included in the product 322, information on the product 322such as a raw material, the place of origin, an inspection result ineach production process, the history of distribution, or an explanationof the article is displayed on the display portion 321. Further, when aproduct 326 is transported by a conveyor belt, the product 326 can beinspected using a reader/writer 324 and an RFID tag 325 provided overthe product 326 (FIG. 14B). Thus, by utilizing such an RFID tag for asystem, information can be acquired easily, and improvement infunctionality and added value of the system can be achieved.

The semiconductor device shown in the embodiment mode is used for asemiconductor device which can wirelessly input and output data, whichleads to easy manufacturing of such a semiconductor device which isthinner and can wirelessly input and output data.

(Embodiment Mode 4)

A semiconductor device of the present invention can be used beingprovided in, for example, paper money, coins, securities, certificates,bearer bonds, packing containers, books, recording media, personalitems, vehicles, food items, clothes, healthcare items, livingwares,medicals, electronic devices, or the like. Examples thereof will bedescribed with reference to FIGS. 15A to 16D.

FIG. 15A shows an example of a state of completed products of ID labelsaccording to the present invention. On a label board (separate paper)118, a plurality of ID labels 20 each incorporating an IC chip 110 areformed. The ID labels 20 are put in a box 119. In addition, on the IDlabel, information on a commercial product or service (for example, aname of the product, a brand, a trademark, a trademark owner, a seller,a manufacturer, and the like) is written, while an ID number that isunique to the commercial product (or the kind of the commercial product)is assigned to the incorporated IC chip to make it possible to easilyfigure out forgery, infringement of intellectual property rights such asa patent and a trademark, and illegality such as unfair competition. Inaddition, a lot of information that is too much to write clearly on acontainer of the commercial product or the label, for example, theproduction area, selling area, quality, raw material, efficacy, use,quantity, shape, price, production method, directions for use, time ofthe production, time of the use, expiration date, instructions of thecommercial product, information on the intellectual property of thecommercial product and the like can be input in the IC chip so that atransactor and a consumer can access the information by using a simplereader. While the producer can also easily rewrite or delete theinformation, a transactor or consumer is not allowed to rewrite ordelete the information.

FIG. 15B shows an ID tag 120, which has an IC chip incorporated. Bymounting the ID tag on commercial products, the management of thecommercial products becomes easier. For example, in the case where thecommercial product is stolen, the thief can be figured out quickly bytracing the pathway of the commercial product. In this way, by providingthe ID tag, commercial products that are superior in so-calledtraceability can be distributed.

FIG. 15C shows an example of a state of a completed product of an IDcard 41 according to the present invention. The ID card includes allkinds of cards such as a cash card, a credit card, a prepaid card, anelectronic ticket, electronic money, a telephone card, and a membershipcard.

FIG. 15D shows an example of a state of a completed product of a bearerbond 122 according to the present invention. The bearer bonds include,but not limited to of course, stamps, tickets, admission tickets,merchandise coupons, book coupons, stationery coupons, beer coupons,rice coupons, various gift coupons, various service coupons. Inaddition, a semiconductor device of the present invention can beprovided in securities such as a check, a certificate and a promissorynote, certificates such as a driving license and a resident card, or thelike, not limited to bearer bonds.

FIG. 15E shows a wrapping film 127 incorporating an IC chip 110, forwrapping a commercial product. The wrapping film 127 can bemanufactured, for example, by scattering IC chips arbitrarily on a lowerfilm and covering them with an upper film. The wrapping film 127 is putin a box 129, and a desired amount of film can be cut away with a cutter128 and used. The material of the wrapping film 127 is not particularlylimited. For example, materials such as a thin film resin, an aluminumfoil, and paper can be used.

FIGS. 16A and 16B respectively show a book 123 and a plastic bottle 124to which an ID label 20 according to the present invention is attached.It is to be noted that the goods are not limited to these and the IDlabel may be attached to various goods such as: containers for packagessuch as paper for packing a box lunch; recording media such as DVDsoftware and a video tape; vehicles including a wheeled vehicle such asa bicycle and a vessel; personal belongings such as a bag and glasses;foods such as food items and beverages; clothes such as clothing andfootwear; healthcare items such as a medical device and a healthappliance; livingware such as furniture and a lighting apparatus;medicals such as a medicine and an agricultural chemical; electronicdevices such as a liquid crystal display device, an EL display device, atelevision set (a television receiver, a thin television receiver), anda mobile phone. The IC chip that is used in the present invention isquite thin, therefore, when the thin film integrated circuit is mountedon goods such as the book, the function or design is not damaged.Furthermore, in the case of a non-contact type thin film integratedcircuit device, an antenna and a chip can be integrated to make iteasier to transfer the non-contact type thin film integrated circuitdevice directly to a commercial product with a curved surface.

FIG. 16C shows a state in which the ID label 20 is directly attached tofresh food such as fruits 131. In addition, FIG. 16D shows an example inwhich fresh food such as vegetables 130 is wrapped in the wrappingfilms. When an ID label is attached to a commercial product, probably,the ID label is peeled off. However, when the commercial product iswrapped in wrapping films, it is difficult to peel off the wrappingfilm, which brings some merit for security.

When an RFID is incorporated in bills, coins, securities, certificates,bearer bonds, and the like, forgery of them can be prevented. When anRFID is equipped in containers for packages, books, recording media,personal belongings, foods, livingware, electronic devices, and thelike, inspection systems, rental systems and the like can be performedmore efficiently. When an RFID is equipped in vehicles, healthcareitems, medicals, and the like, forgery and theft of them can beprevented and medicines can be prevented from being taken in the wrongmanner. An RFID may be attached to the surface of a product or embeddedinto a product. For example, an RFID may be embedded in the paper of abook, or an organic resin of a package.

In this manner, when the RFID is equipped in containers for packages,recording media, personal belongings, foods, clothes, livingware,electronic devices, and the like, inspection system, rental system andthe like can be performed more efficiently. The RFID also preventsvehicles from being forged or stolen. In addition, when the RFID isimplanted into creatures such as animals, each creature can beidentified easily. For example, when the RFID is implanted in creaturessuch as domestic animals, the year of birth, sex, breed and the like canbe easily identified.

As described above, the semiconductor device of the present inventioncan be used for any product. Since the semiconductor device of thepresent invention is thinner and more bendable, a user can use naturallya product with the semiconductor device attached. Note that thisembodiment mode can be freely combined with the other embodiment modesand embodiments.

This application is based on Japanese Patent Application serial no.2006-175611 filed in Japan Patent Office on Jun. 26, 2006 the entirecontents of which are hereby incorporated by reference.

What is claimed is:
 1. A semiconductor device comprising: an element formation layer over a substrate; an antenna over the element formation layer; and a protective layer over the element formation layer and the antenna, wherein the element formation layer comprises a plurality of circuits, wherein an electromagnetic wave supplies a power source voltage to each of the plurality of circuits, and wherein a value in a thickness ratio of the protective layer in a portion not covering the antenna to the antenna is at least 1.2.
 2. The semiconductor device according to claim 1, wherein the protective layer comprises epoxy resin.
 3. The semiconductor device according to claim 1, wherein the substrate has a thickness of 2 μm to 20 μm.
 4. The semiconductor device according to claim 1, wherein an adhesive layer is provided between the substrate and the element formation layer.
 5. The semiconductor device according to claim 1 wirelessly transmits signals by electromagnetic coupling method, an electromagnetic induction method or a microwave method.
 6. A semiconductor device comprising: an element formation layer over a substrate; a storage element portion over the substrate; an antenna over the element formation layer; and a protective layer provided over the element formation layer, the storage element portion and the antenna, wherein the element formation layer comprises a circuit for writing in data into the storage element portion and reading out data from the storage element portion, wherein the element formation layer comprises a plurality of circuits, wherein an electromagnetic wave supplies a power source voltage to each of the plurality of circuits, and wherein a value in a thickness ratio of the protective layer in a portion not covering the antenna to the antenna is at least 1.2.
 7. The semiconductor device according to claim 6, wherein the protective layer comprises epoxy resin.
 8. The semiconductor device according to claim 6, wherein the substrate has a thickness of 2 μm to 20 μm.
 9. The semiconductor device according to claim 6, wherein an adhesive layer is provided between the substrate and the element formation layer.
 10. The semiconductor device according to claim 6 wirelessly transmits signals by electromagnetic coupling method, an electromagnetic induction method or a microwave method.
 11. A semiconductor device comprising: an element formation layer over a substrate; an antenna over the element formation layer; and a protective layer over the element formation layer and the antenna, wherein the element formation layer comprises a plurality of circuits and a battery, wherein an electromagnetic wave or the battery supplies a power source voltage to each of the plurality of circuits, and wherein a value in a thickness ratio of the protective layer in a portion not covering the antenna to the antenna is at least 1.2.
 12. The semiconductor device according to claim 11, wherein the protective layer comprises epoxy resin.
 13. The semiconductor device according to claim 11, wherein the substrate has a thickness of 2 μm to 20 μm.
 14. The semiconductor device according to claim 11, wherein an adhesive layer is provided between the substrate and the element formation layer.
 15. The semiconductor device according to claim 11 wirelessly transmits signals by electromagnetic coupling method, an electromagnetic induction method or a microwave method.
 16. A semiconductor device, comprising: an element formation layer over a substrate; a storage element portion over the substrate; an antenna over the element formation layer; and a protective layer provided over the element formation layer, the storage element portion and the antenna, wherein the element formation layer comprises a circuit for writing in data into the storage element portion and reading out data from the storage element portion, wherein the element formation layer comprises a plurality of circuits and a battery, wherein an electromagnetic wave or the battery supplies a power source voltage to each of the plurality of circuits, and wherein a value in a thickness ratio of the protective layer in a portion not covering the antenna to the antenna is at least 1.2.
 17. The semiconductor device according to claim 16, wherein the protective layer comprises epoxy resin.
 18. The semiconductor device according to claim 16, wherein the substrate has a thickness of 2 μm to 20 μm.
 19. The semiconductor device according to claim 16, wherein an adhesive layer is provided between the substrate and the element formation layer.
 20. The semiconductor device according to claim 16 wirelessly transmits signals by electromagnetic coupling method, an electromagnetic induction method or a microwave method. 